<template>
    <div class='sub-sort'>
      <div class="sort">
        <a :class="{active:sortParams.sortField===null}" @click="changeSort(null)" href="javascript:;">默认排序</a>
        <a :class="{active:sortParams.sortField==='publishTime'}" @click="changeSort('publishTime')" href="javascript:;">最新商品</a>
        <a :class="{active:sortParams.sortField==='orderNum'}" @click="changeSort('orderNum')" href="javascript:;">最高人气</a>
        <a :class="{active:sortParams.sortField==='evaluateNum'}" @click="changeSort('evaluateNum')" href="javascript:;">评论最多</a>
        <a @click="changeSort('price')" href="javascript:;">
          价格排序
          <i class="arrow up" :class="{active:sortParams.sortField==='price'&&sortParams.sortMethod=='asc'}" />
          <i class="arrow down" :class="{active:sortParams.sortField==='price'&&sortParams.sortMethod=='desc'}" />
        </a>
      </div>
      <div class="check">
        <XtxCheckbox @change="changeCheck"  v-model="sortParams.inventory">仅显示有货商品</XtxCheckbox>
        <XtxCheckbox @change="changeCheck"  v-model="sortParams.onlyDiscount">仅显示特惠商品</XtxCheckbox>
      </div>
    </div>
  </template>
  <script>
  import { reactive } from 'vue'
  export default {
    name: 'SubSort',
    setup (props,{emit}) {
      // 1. 根据后台需要的参数定义数据对象
      // 2. 根据数据对象，绑定组件（复选框，排序按钮）
      // 3. 在操作排序组件的时候，需要反馈给数据对象
      // sortField====>publishTime,orderNum,price,evaluateNum
      // sortMethod====>asc为正序 desc为倒序
      const sortParams = reactive({
        inventory: false,
        onlyDiscount: false,
        sortField: null,
        sortMethod: null
      })
  
      // 改变排序
      const changeSort = (sortField) => {
        if (sortField === 'price') {
          sortParams.sortField = sortField
          if (sortParams.sortMethod === null) {
            // 第一次点击，默认是降序
            sortParams.sortMethod = 'desc'
          } else {
            // 其他情况根据当前排序取反
            sortParams.sortMethod = sortParams.sortMethod === 'desc' ? 'asc' : 'desc'
          }
        } else {
          // 如果排序未改变停止逻辑  
          if (sortParams.sortField === sortField)  return
          sortParams.sortField = sortField
          sortParams.sortMethod = null
        }
        emit('sort-change', sortParams)
      }
      const changeCheck = (sortField) => {
      emit('sort-change', sortParams)
    }
  
      return { sortParams, changeSort ,changeCheck}
    }
  }
  </script>
<style scoped lang='less'>
.sub-sort {
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: space-between;

    .sort {
        display: flex;

        a {
            height: 30px;
            line-height: 28px;
            border: 1px solid #e4e4e4;
            padding: 0 20px;
            margin-right: 20px;
            color: #999;
            border-radius: 2px;
            position: relative;
            transition: all .3s;

            &.active {
                background: @xtxColor;
                border-color: @xtxColor;
                color: #fff;
            }

            .arrow {
                position: absolute;
                border: 5px solid transparent;
                right: 8px;

                &.up {
                    top: 3px;
                    border-bottom-color: #bbb;

                    &.active {
                        border-bottom-color: @xtxColor;
                    }
                }

                &.down {
                    top: 15px;
                    border-top-color: #bbb;

                    &.active {
                        border-top-color: @xtxColor;
                    }
                }
            }
        }
    }

    .check {
        .xtx-checkbox {
            margin-left: 20px;
            color: #999;
        }
    }
}
</style>